<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>这是一个 不灵不灵的按钮 </title>
  <style>
    .btn {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      width: 230px;
      height: 90px;
      line-height: 90px;
      text-align: center;
      color: #fff;
      font-size: 24px;
      text-transform: uppercase;
      text-decoration: none;
      font-family: sans-serif;
      box-sizing: border-box;
      background: linear-gradient(90deg, #03a9f4, #f441a5, #ffeb3b, #03a9f4);
      background-size: 400%;
      border-radius: 60px;
      z-index: 1;
    }
    
    .btn:hover {
      animation: animate 8s linear infinite;
    }
    
    @keyframes animate {
      0% {
        background-position: 0%;
      }
      100% {
        background-position: 400%;
      }
    }
    
    .btn::before {
      content: '';
      position: absolute;
      top: -5px;
      left: -5px;
      right: -5px;
      bottom: -5px;
      z-index: -1;
      background: linear-gradient(90deg, #03a9f4, #f441a5, #ffeb3b, #03a9f4);
      background-size: 400%;
      border-radius: 40px;
      opacity: 0;
      transition: 0.5s;
    }
    
    .btn:hover::before {
      filter: blur(20px);
      opacity: 1;
      animation: animate 30s linear infinite;
    }
  </style>
</head>
<body>
  <a href="#" class="btn">button</a>
</body>
</html>
<script type="text/javascript">
	
	
	function feibonaqie(n){
         if(n===1||n===2){
           return 1
         }
           return feibonaqie(n-1)+feibonaqie(n-2)
         }
         console.log(feibonaqie(5))    //5
				// console.log(feibonaqie(9))    //34 
</script>